1. Field of the Invention
The present invention relates to an image communication apparatus which can be connected to a plurality of speech communication terminals.
2. Related Background Art
In a conventional communication system, telephone sets and facsimile machines are connected to a predetermined transmission line such as one or a plurality of subscriber telephone lines.
A system of this type is used in an office. In this case, telephone sets are respectively installed on desks of the operators, and one or two facsimile machines are installed at other locations and can be commonly operated by a plurality of operators. Earlier filed patent applications associated with the system of this type and filed by the present applicant are U.S. Ser. No. 823,286 (filed Jan. 28, 1986) now U.S. Pat. No. 4,825,461, U.S. Ser. No. 108,915 (filed Oct. 15, 1987) and U.S. Ser. No. 106,783 (filed Oct. 13, 1987).
Although a line control function for controlling outgoing and incoming calls is commonly utilized in such a system, the communication function is effected by the telephone sets and the image communication function is effected by the facsimile machines. In this manner, two communication functions are perfectly independent in accordance with types of terminal devices due to the following reason.
When a telephone set is arranged together with a facsimile machine to constitute a single unit, the resultant device is too large to be installed on a desk. In addition, some operators do not want image communication. Therefore, the resultant terminal unit may include unnecessary functions.
When facsimile communication is performed in a communication apparatus, each operator moves from his desk to the installation place of the facsimile machine and must perform required operations, resulting in cumbersome, time-consuming operations.
Therefore, strong demand has arisen for a communication system wherein a terminal on an operator's desk is not excessively large, cost of the terminal device can be reduced, and image communication can be performed at the desk with simple operations.